[U-Boot-Users] debug linux kernel hangs

[Alex shi]

Hi Denk:     Sorry, I did not notice it.Hi all:
     My platform is MPC8247, u-boot verison is 1.1.1 and linux kernel version is 2.4.22
 in the serial console I load the linux kernel and want to boot it under u-boot:
 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
 => setenv ethaddr 00:01:02:03:04:05
 => setenv ipaddr 192.168.0.33
 => setenv serverip 192.168.0.222
 => tftp 0x100000 uImage
 Using FCC1 ETHERNET device
 TFTP from server 192.168.0.222; our IP address is 192.168.0.33
 Filename "uImage".
 Load address: 0x100000
 Loading: #################################################################
          #################################################################
          #####################################
 done
 Bytes transferred = 853098 (d046a hex)
 => bootm 0x100000
 ## Booting image at 00100000 ...
    Image Name:   Linux Kernel Image
    Image Type:   PowerPC Linux Kernel Image (gzip compressed)
    Data Size:    853034 Bytes = 833 kB
    Load Address: 00000000
    Entry Point:  00000000
    Verifying Checksum ... OK
    Uncompressing Kernel Image ... OK
 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
 but after print the "Uncompressing Kernel Image ... OK" msg, the kernel hangs.
 I use the same u-boot.h file under linux kernel and u-boot, and sure the bd_info in them
are same. 
 IMMR address also are same at 0xf0000000.
 
 My bdi2000 run and print below:
 ++++++++++++++++++++++++++++++++++
 8272>i
     Target CPU        : MPC8280/8220/5200 (Zeppo)
     Target state      : debug mode
     Debug entry cause : COP freeze (startup)
     Current PC        : 0xfff00100
     Current CR        : 0x00000000
     Current MSR       : 0x00001042
     Current LR        : 0x00000000
 8272>g
 8272>h
     Target CPU        : MPC8280/8220/5200 (Zeppo)
     Target state      : debug mode
     Debug entry cause : COP halt
     Current PC        : 0x07fe94c8
     Current CR        : 0x84002024
     Current MSR       : 0x0000b002
     Current LR        : 0x07fda464
 8272>bi 0xc01554c8    (which is the start_kernel_address)
 Breakpoint identification is 1
 8272>g
 - TARGET: stopped
 8272>i
     Target CPU        : MPC8280/8220/5200 (Zeppo)
     Target state      : debug mode
     Debug entry cause : <reserved 0>
     Current PC        : 0x001cbde4
     Current CR        : 0x24008084
     Current MSR       : 0x00003002
     Current LR        : 0x00000028
 +++++++++++++++++++++++++++++++++++++++++++
 
 Why the Current PC can not get the start_kernel address? How can i to debug the linux
kernel?
 Any hits will be very appreciated!
 
 BRG
 Alexander